Because omega-3 fatty acids, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and their metabolites are known to possess anti-inflammatory and health-promoting functions in human and experimental animals, their intake is assumed to be beneficial for maintaining our health. We previously identified a cytochrome P450-metabolite of EPA, 5,6-dihydroxy-8Z,11Z,14Z,17Z-eicosatetraenoic acid (5,6-DiHETE), as a novel bioactive lipid, which inhibits vascular hyperpermeability in inflammation. Because blue back fishes including sardine, mackerel, and horse mackerel are reported to contain high concentrations of omega-3 fatty acids, we investigated which tissue of blue back fish is suitable as a source of 5,6-DiHETE. We measured the concentration of 5,6-DiHETE as well as major fatty acids in muscle, bone, heart, liver, and intestine of blue back fishes. Arachidonic acid was detected richer in intestines than other tissues of blue back fishes. The concentrations were between 4.45 and 5.62 µg/g tissue weight. EPA and DHA are also detected richer in intestines of blue back fishes. The concentrations were between 75.95 and 358.04 µg/g, and 203.09 and 464.88 µg/g, respectively. Especially, mackerel intestine contained the highest levels of both EPA and DHA. 5,6-DiHETE was present in greater amount in livers and intestines of blue back fishes. The livers contained 118.98 to 476.11 ng/g, whereas intestines contained 156.14 to 970.22 ng/g of 5,6-DiHETE. Of interest, sardine intestine contained much higher level of 5,6-DiHETE than the other fish tissues. These results suggest that visceral organs of blue back fishes, remarkably sardine intestine, can be a good source of 5,6-DiHETE. PRACTICAL APPLICATION: A novel anti-inflammatory lipid, 5,6-DiHETE, was detected in each tissues of blue back fishes. Especially their intestines contain the highest concentration of this lipid.

中文翻译：

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一种新型二十碳五烯酸衍生的抗炎脂质介质 5,6-DiHETE 在蓝背鱼肠道中含量丰富

由于已知 omega-3 脂肪酸、二十碳五烯酸 (EPA)、二十二碳六烯酸 (DHA) 及其代谢物在人类和实验动物中具有抗炎和促进健康的功能，因此认为它们的摄入有益于维持我们的健康。我们之前鉴定了 EPA、5,6-二羟基-8Z,11Z,14Z,17Z-二十碳四烯酸 (5,6-DiHETE) 的细胞色素 P450 代谢物，作为一种新型生物活性脂质，可抑制炎症中的血管通透性过高。由于据报道包括沙丁鱼、鲭鱼和竹荚鱼在内的蓝背鱼含有高浓度的 omega-3 脂肪酸，因此我们调查了蓝背鱼的哪些组织适合作为 5,6-DiHETE 的来源。我们测量了 5,6-DiHETE 以及肌肉、骨骼、心脏、肝脏、和蓝背鱼的肠子。检测到的花生四烯酸比蓝背鱼的其他组织更丰富。浓度介于 4.45 和 5.62 µg/g 组织重量之间。在蓝背鱼的肠道中也检测到 EPA 和 DHA 含量更高。浓度分别介于 75.95 和 358.04 µg/g 之间，以及 203.09 和 464.88 µg/g 之间。尤其是鲭鱼肠中的EPA和DHA含量最高。5,6-DiHETE 在蓝背鱼的肝脏和肠道中含量更高。肝脏含有 118.98 至 476.11 ng/g，而肠道含有 156.14 至 970.22 ng/g 5,6-DiHETE。有趣的是，沙丁鱼肠含有比其他鱼类组织高得多的 5,6-DiHETE。这些结果表明，蓝背鱼的内脏器官，特别是沙丁鱼肠，可以是 5,6-DiHETE 的良好来源。实际应用：在蓝背鱼的每个组织中检测到一种新型抗炎脂质，5,6-DiHETE。特别是它们的肠道含有最高浓度的这种脂质。